tests/intrusive_shared_ptr_src/cast.reinterpret.cpp

   1 //
   2 // Tests for
   3 //  template<typename To, typename From, typename R>
   4 //  intrusive_shared_ptr<To, R> reinterpret_pointer_cast(intrusive_shared_ptr<From, R> const& ptr) noexcept;
   5 //
   6 //  template<typename To, typename From, typename R>
   7 //  intrusive_shared_ptr<To, R> reinterpret_pointer_cast(intrusive_shared_ptr<From, R>&& ptr) noexcept
   8 //
   9
  10 #include <libkern/c++/intrusive_shared_ptr.h>
  11 #include <utility>
  12 #include <darwintest.h>
  13 #include "test_policy.h"
  14
  15 struct Base { int i; };
  16 struct Derived : Base { };
  17
  18 // Layout compatible with Derived
  19 struct Unrelated { int i; };
  20
  21 template <typename Stored, typename From, typename To>
  22 static void
  23 tests()
  24 {
  25         Stored obj{3};
  26
  27         {
  28                 tracked_shared_ptr<From> const from(&obj, libkern::no_retain);
  29                 tracking_policy::reset();
  30                 tracked_shared_ptr<To> to = libkern::reinterpret_pointer_cast<To>(from);
  31                 CHECK(tracking_policy::retains == 1);
  32                 CHECK(tracking_policy::releases == 0);
  33                 CHECK(to.get() == reinterpret_cast<To const*>(&obj));
  34                 CHECK(from.get() == &obj);
  35         }
  36         {
  37                 tracked_shared_ptr<From> from(&obj, libkern::no_retain);
  38                 tracking_policy::reset();
  39                 tracked_shared_ptr<To> to = libkern::reinterpret_pointer_cast<To>(std::move(from));
  40                 CHECK(tracking_policy::retains == 0);
  41                 CHECK(tracking_policy::releases == 0);
  42                 CHECK(to.get() == reinterpret_cast<To const*>(&obj));
  43                 CHECK(from.get() == nullptr);
  44         }
  45
  46         // Test `reinterpret_pointer_cast`ing a null pointer
  47         {
  48                 tracked_shared_ptr<From> const from = nullptr;
  49                 tracking_policy::reset();
  50                 tracked_shared_ptr<To> to = libkern::reinterpret_pointer_cast<To>(from);
  51                 CHECK(tracking_policy::retains == 0);
  52                 CHECK(tracking_policy::releases == 0);
  53                 CHECK(to.get() == nullptr);
  54                 CHECK(from.get() == nullptr);
  55         }
  56         {
  57                 tracked_shared_ptr<From> from = nullptr;
  58                 tracking_policy::reset();
  59                 tracked_shared_ptr<To> to = libkern::reinterpret_pointer_cast<To>(std::move(from));
  60                 CHECK(tracking_policy::retains == 0);
  61                 CHECK(tracking_policy::releases == 0);
  62                 CHECK(to.get() == nullptr);
  63                 CHECK(from.get() == nullptr);
  64         }
  65 }
  66
  67 T_DECL(cast_reinterpret, "intrusive_shared_ptr.cast.reinterpret") {
  68         tests</*stored*/ Derived, /*from*/ Derived, /*to*/ Base>();
  69         tests</*stored*/ Derived, /*from*/ Derived const, /*to*/ Base const>();
  70
  71         tests</*stored*/ Derived, /*from*/ Derived, /*to*/ char>();
  72         tests</*stored*/ Derived, /*from*/ Derived const, /*to*/ char const>();
  73
  74         tests</*stored*/ Derived, /*from*/ Derived, /*to*/ Unrelated>();
  75         tests</*stored*/ Derived, /*from*/ Derived const, /*to*/ Unrelated const>();
  76 }